The overall objective of the project is the development of novel antitumor agents for use in the treatment of certain human mammary tumors. The aims include the isolation of steroid alcohol sulfotransferase, the synthesis of transition state (multisubstrate) analogs of steroid sulfurylation, the characterization of these analogs in terms of the appropriate steroid sulfotransferase, and evaluation of selected steroid derivatives on dimethylbenzanthracene (DMBA) tumors in the rat.